This invention relates to an electrical connector intended for use with terminal blocks commonly employed as a means of,connection for wire networks. More specifically, this invention relates to an alternate means, namely a patch connector, for making electrical connection between wire and terminal points without the aid of tools or soldering.
In the communication industry, and more particularly in the telephone and data transmission industry, terminal blocks having a plurality of clip type electrical connectors or terminals protruding therefrom are commonly used. One such terminal block is the well known type 110 connecting block. Examples of 110 terminal blocks are described in U.S. Pat. Nos. 3,798,587 and 4,964,812, both of which are incorporated herein by reference. Having become widely accepted over the last ten years or so, the 110-type quick connect blocks have evolved into many shapes and sizes and have been the focal point of a variety of accessories and adapters.
Test adapters that plug onto the front of the terminal block such as disclosed in U.S. Pat. No. 4,878,848 may be used to connectorize the terminals with modular jacks or other industry standard connectors. The limitation of these devices is that they cannot always be field wired and they cannot always be mounted end to end or side to side without missing terminal locations that may require access. An example of another such test adapter for 66 type connector blocks is described in U.S. Pat. No. 4,585,290, which is assigned to the assignee hereof. Other examples of prior art test adapters are discussed in U.S. Pat. No. 4,585,290.
While the connection points on the terminal block may be capable of terminating wire directly via a solder joint or insulation displacement, well known patch connectors provide a means for making additional connections for temporary or long term use. Once wired, a patch connector is a multiple wire connector that may be installed and removed from the terminal block for the purpose of branching off existing lines or connecting together discrete areas of the terminal field.
Improved terminal block patching devices which allow for field wiring are disclosed in U.S. Pat. No. 4,759,723 and U.S. Pat. No. 4,834,669, both of which are assigned to the assignee hereof and incorporated herein by reference. While well suited for their intended purposes, these prior patch connectors are designed primarily for use in connection with terminal blocks incorporating type 66 terminals. However, there is a need for a low cost and reliable patch connector which can be field terminated and which can be used with other types of terminal blocks.
Other patch connectors are available that provide means for accomplishing connections between shielded twisted-pair cables. One such patch connector is disclosed in U.S. Pat. No. 5,160,273 ('273). It will be appreciated that the patch connector of the '273 patent relies on a printed circuit board to provide connections to both signal carriers and to shield conductors. One limitation of the '273 patent is that it requires an additional connection between the cable shield termination means and the printed circuitry. This added connection, plus the complex geometry of the circuit path, combined with the limited surface available for the shield path, due to the presence of signal traces on the printed circuit board, results in limited high frequency shield effectiveness. An additional limitation of the '273 patent is that it requires the use of a specialized receptacle in order to accomplish connections to both signal carriers and the shield, and, therefore is not compatible with the well known 110 type connector. Other prior art patch connectors exist that are intended to plug onto 110-style connecting blocks, but these connectors are encumbered by limitations of their own. In particular, they lack provisions for shield terminations. Also, their design, and means of cable preparation and termination make them difficult to use in the field and still provide Category 5 transmission performance as defined in TIA/EIA TSB40.
The "cross-over lead" technique used in prior art 110 patch products to achieve Category 5 performance requires that twisted pair conductors be terminated in a different sequence on the patch connector than on the 110 connecting block to which it connects. This limitation, combined with the physical difficulty with placing precut wires in their respective termination slots while maintaining pair twists as close as possible to the point of termination, as is necessary to achieve Category 5 performance, makes field termination impractical. Still other 110-type patch connectors are available that are capable of field terminations, but these connectors do not offer Category 5 transmission performance. Heretofore, no prior art 110-type patch connectors offer provisions for shield connection.
Therefore, it will be appreciated that there is a need for a patch connector which can mate with the 110-type connecting blocks and make optional connections to cable shielding and which can provide Category 5 transmission performance while preserving the capability for terminations by installers and technicians in the field.